iommu/arm-smmu-qcom: Add stall support

Add, via the adreno-smmu-priv interface, a way for the GPU to request
the SMMU to stall translation on faults, and then later resume the
translation, either retrying or terminating the current translation.

This will be used on the GPU side to "freeze" the GPU while we snapshot
useful state for devcoredump.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Acked-by: Jordan Crouse <jordan@cosmicpenguin.net>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20210610214431.539029-5-robdclark@gmail.com
Signed-off-by: Rob Clark <robdclark@chromium.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/linux/adreno-smmu-priv.h b/include/linux/adreno-smmu-priv.h
index 53fe32fb9214..c637e0997f6d 100644
--- a/include/linux/adreno-smmu-priv.h
+++ b/include/linux/adreno-smmu-priv.h
@@ -45,6 +45,11 @@ struct adreno_smmu_fault_info {
  *                 TTBR0 translation is enabled with the specified cfg
  * @get_fault_info: Called by the GPU fault handler to get information about
  *                  the fault
+ * @set_stall:     Configure whether stall on fault (CFCFG) is enabled.  Call
+ *                 before set_ttbr0_cfg().  If stalling on fault is enabled,
+ *                 the GPU driver must call resume_translation()
+ * @resume_translation: Resume translation after a fault
+ *
  *
  * The GPU driver (drm/msm) and adreno-smmu work together for controlling
  * the GPU's SMMU instance.  This is by necessity, as the GPU is directly
@@ -60,6 +65,8 @@ struct adreno_smmu_priv {
     const struct io_pgtable_cfg *(*get_ttbr1_cfg)(const void *cookie);
     int (*set_ttbr0_cfg)(const void *cookie, const struct io_pgtable_cfg *cfg);
     void (*get_fault_info)(const void *cookie, struct adreno_smmu_fault_info *info);
+    void (*set_stall)(const void *cookie, bool enabled);
+    void (*resume_translation)(const void *cookie, bool terminate);
 };
 
 #endif /* __ADRENO_SMMU_PRIV_H */